1. Field of The Invention
This invention relates to explosively activated T-joint pipe fittings.
2. Description of the Prior Art
There are several designs of T-joints applicable to pipes for making it possible in an easy way to provide a branch conduit, without having to disconnect or empty the piping. The housing of the T-joint contains a member having a sharp edge for cutting a hole in the pipe and an explosive charge for actuating the cutting member.
The selection of the size and also the location of the charge requires some consideration, and it is deemed important that the charge, within the very limited explosion chamber available shall be able to cover a major part of the back face of the cutting member.
U.S. Pat. No. 4,261,384 held by the assignee of the present invention shows a favourable arrangement of a charge contained in a cartridge, which is easily, fitted between the nut and the housing. The shape of the cartridge is to some degree determined by a desire to provide access for a spindle to rotate the cutting member afterwards, in order to make the same serviceable as a valve body for occasionally blocking the branch conduit. The cost of the cartridge is furthermore rather high.